Muffling system for compressed airoperated drilling apparatus



May 28, 1968 E. H. KURT ET AL 3,385,395

MUFFLING SYSTEM FOR COMPRESSED AIR-OPERATED DRILLING APPARATUS Filed May 2, 1966 4 Sheets-Sheet l E mi i/ o I} o 8 M J v a m H L L o 9 v o 0O) 0 INVENTORS EWALD H. KURT GEORGE Mi D/EHL BY QM wT-Jm ATTORNEY May 28, 1968 KURT ET 3,385,395

MUFFLING SYSTEM FOR COMPRESSED AIR-OPERATED DRILLING APPARATUS 4 Sheets-Sheet 2 Filed May 2, 1966 May 28, 1968 v KURT ET 3,385,395

MUFFLING SYSTEM FOR COMPRESSED AIR-OPERATED DRILLING APPARATUS Filed May 1966 4 Sheets-Sheet 28 A '1' w I4 w W MG 6 .1 .ltu.|m..., J 7

INVENTORS EWALD H. KURT G JORGE-M. DIE/IL @o -QX hl'TMW ATTORNEY May 28, 1968 U ET AL 3,385,395

MUEFLING SYSTEM FOR COMPRESSED AIR-OPERATED DRILLING APPARATUS Filed May a, 1966 4 Sheets-Shet 4 M WI '1 2| 1 2| 2 l2- 3 2 FN 20 f 27 30 3 I fi w 1 L n 2e 5 M9 1 f 12 2| 1 l8 f F 1 L F/ 6. 5 I37 A INVENTORS r23 1% hffim 23 i 25 BY K Q-MQ ATTORNEY United States Patent 3,385,395 MUFFLING SYSTEM FOR COMPRESSED AIR- OPERATED DRILLING APPARATUS Ewald H. Kurt and George M; Diehl, Phillipsburg, NJ.,

assignors to Ingersoll-Rand Company, New York, N.Y.,

a corporation of New Jersey Filed May 2, 1966, Ser. No. 546,774 9 Claims. (Cl. 181-36) ABSTRACT OF THE DISCLOSURE A rock drill mounting having the exhaust port of a drill motor connected to mufiiing passages running the length of the drill motor guide and exiting into a plenum chamber mounted at the top end of the drill guide.

This invention relates generally to the art of compressed air-operated motors, such as is used for rock drilling purposes and, more particularly, to systems for muffling the exhaust noises created by compressed air operated motors.

The drilling industry is faced with an increasing exhaust noise problem as drill motors become larger and are operated with increased air volume rates and higher pressures. At the present time, most drillers operate their drilling equipment without mufiling devices on the exhaust ports of the drill motors, although the advantages of muffiing the exhaust of a compressed air drill motor are well recognized. This result is probably due to the disadvantages of conventional mufiiing devices. Generally, conventional mufiling devices are relatively large and unwieldy, and they produce a substantial restriction in the exhaust air flow, thus reducing the operating efficiency of the air motor. It appears that owners and operators of drilling equipment would rather forego the advantage of mufiling the exhaust of drill motors than be burdened with the disadvantages provided by conventional muffling devices.

The principal object of this invention is to provide an exhaust system for compressed air drill motors which either minimizes or substantially eliminates the disadvantages provided by conventional muflling devices.

Further important objects of this invention are: to provide a drill motor rnufiier which does not substantially restrict the flow of exhaust air from the motor; to provide a drill motor mufller which provides little or no increase in size of the drilling apparatus; to provide a drill motor mufiler which utilizes spaces and passages previously present in conventional drilling apparatus; and to provide a drill motor muflling system which conveys the exhaust air and noise away from the drill operator.

Briefly, these objects are attained by piping the air exhausted from the drill motor to an interior space provided in a frame normally forming a part of the drill apparatus, such as a drill guide slidably supporting the drill motor. Conveying the exhaust air through the spaces or passages in the frame aids in substantially reducing the velocity of the exhausted air and absorbing substantial amounts of noise carried by or created by the exhausted air. The frame is arranged to eventually exhaust the exhaust air at a point remote from the operator of the drill. By utilizing the internal passages normally provided in a drill apparatus for muffiing purposes, we eliminate the need for adding substantial additional structure to the drilling apparatus which would substantially increase its size, bulk and weight.

The invention is described in connection with the accompanying drawings wherein:

FIG. 1 is a perspective view of a crawler-type drilling apparatus using the muffling system of this invention;

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FIG. 2 is a front elevation of the drill guide and drill motor, shown in FIG. 1;

FIG. 3 is a side elevation of the drill guide and motor, shown in FIG. 2;

FIGS. 4, 5 and 6 are sections taken, respectively, on lines 44, 55 and 6-6 of FIG. 3;

FIG. 7 is an enlarged front elevation with portions cut away of the drill guide shown in the preceding figures; and

FIG. 8 is an enlarged fragmentary side-elevation with portions cut away of the upper end portion of the drill guide.

The crawler-type drill apparatus 1 shown in FIG. 1 includes a chassis 2 mounted on a pair of crawler tracks 3 and a boom 4 mounted on the chassis 2 and carrying a drill guide 5. The drill guide 5 includes a foot 6 at its lower end, as shown in FIG. 1, and a drill motor 7 slidably mounted for travel along the drill guide 5. The drill motor 7 drives a drill rod 8 which extends through a drill rod centralizer 9 mounted on the lower end of the drill guide 5. The drill guide 5 further carries a control console 11 near its lower end at a position where an operator can stand beside the drill guide 5 and operate the drill during the drilling of a hole. All of the foregoing structure is conventional in the rock drilling art.

The drill guide 5 includes a pair of elongate beams 12 rigidly connected together in parallel and spaced relationship by several cross struts 13, as shown in FIG. 7. The drill guide 5 carries an endless feed chain 14 riding on a pair of sprockets 15 located at the opposite ends of the drill guide 5 between the spaced beams 12 for feeding the drill motor 7 back and forth along the drill guide 5. This arrangement of the drill guide 5 is conventional in the prior art.

The invention in this application resides in a muflling system for handling the air exhausted from the drill motor 7. The drill motor 7 includes an exhaust port 17 connected to a flexible exhaust hose 18 which is supported at its other end to a hose support bracket 19 fixed on the side of one of the beams 12. The bracket 19 is located on the drill guide 5 at a point spaced about one quarter of the length of the drill guide 5 from its upper end, as shown in FIG. 1. The hose 18 is of suflicient length to allow the drill motor 7 to move along substantially the entire length of the drill guide 5 without interference. The end of the hose 18 supported on the bracket 19 is connected to a pipe elbow 20' which feeds into an elongate passage 21 provided in the drill guide beam 12 supporting the bracket 19.

Both of the drill guide beams 12 contain respective elongate passages 21 whilch are formed by providing each beam 12 with a box-like cross section. It will be recog nized that the beam 12 could have various cross sections and configurations to provide the elongate passages 21. This embodiment has the cross section configuration illustrated in FIGS. 4 to 6 wherein a large channel beam is combined with a smaller channel beam welded to the web of the larger channel beam.

The elongate passage 21 in each beam 12 is closed at its opposite ends, respectively, by a bottom plate 23 and a top plate 24, both welded in the interior of the beam 12. The bottom plate 23 contains several small drain holes 25 for draining any liquid, such as water, accumulating in the passage 21. The passages 21 in both beams 12 are interconnected by a cross pipe 27 located opposite the exhaust opening of the pipe elbow 20, as shown in FIG. 7.

Exhaust air exiting from the pipe 20 into the drill guide 5 will flow simultaneously into both of the elongate passages 21. These two passages 21 combine to provide a substantial amount of volume for reducing the velocity of the exhaust air as well as absorbing a large amount of the noise carried or created by the flowing exhaust air.

After the exhaust air flows through the two elongate passages 21 and is substantially reduced in velocity, it flows out respective exhaust outlets 28 located near the upper end of the passages 21. Each exhaust outlet opens into a plenum chamber 30 of substantial size mounted on the rear face of the upper end of the drill guide 5. The plenum chamber 30 contains enough volume to further substantially reduce the noise created by the exhaust air. The air exhausts from the plenum chamber 30 through an exhaust opening 31 provided at the top of the plenum chamber 30. The exhaust opening 31 is shielded by a spaced roof 32 to aid in preventing rain from falling into the opening 31 and, also, to form a further bafile aiding in the mufiiing of the exhaust air.

Although a single embodiment of the invention is illustrated and described in detail, it will be understood that the invention is not limited simply to this embodiment, but contemplates other embodiments and variations which utilize the concepts and teachings of this invention.

Having described our invention, we claim:

1. A compressed air-operated drilling apparatus comprising:

a frame including a hollow space of substantial volume; a compressed air-operated drill motor mounted on said frame and including an exhaust port;

a conduit interconnecting said exhaust port to said hollow space in said frame for feeding the air exhausted from said motor into said hollow space;

an exhaust outlet provided in said frame for exhausting said hollow space;

said hollow space being of sufficient volume to substantially reduce the noise of the air exhausted from said drill motor before exhausting it through said exhaust outlet;

said frame including an elongate drill guide slidably supporting said drill motor; and

said hollow space being an elongate passage contained in said drill guide and extending substantially the entire length of said drill guide.

2. The drilling apparatus of claim 1 wherein:

said exhaust outlet is located on said frame at a relatively remote distance from the normal position of an operator of the apparatus.

3. The drilling apparatus of claim 2 including:

a plenum chamber mounted on said frame and connected to said exhaust outlet; and

said plenum chamber having an opening for exhaust ing its interior to atmosphere.

4. The drilling apparatus of claim 3 wherein:

said plenum chamber includes suificient volume to sub stantially reduce the velocity of the exhaust air before'said exhaust air flows through said opening into the atmosphere.

5. The drilling apparatus of claim 1 wherein:

said conduit is a flexible hose interconnecting said exhaust port of said drill motor to said elongate passage and being of sufiicient length to allow said drill motor to move along said drill guide without interference.

6. The drilling apparatus of claim 1 wherein:

said drill guide includes a pair of elongate beams mounted together in a spaced parallel relationship with each beam containing an elongate passage connected to said conduit and to each other.

7. The drilling apparatus of claim 6 wherein:

at least one end of each of said elongate passages contains a small drain hole for draining water or other liquid from the passage.

8. The drilling apparatus of claim 6 including:

drill centralizer means at one end of said drill guide for supporting a drill rod for drilling purposes; and

said exhaust outlet for said passages being located at the opposite end of said drill guide from said drill centralizer means.

9. The drilling apparatus of claim 8 including:

a plenum chamber mounted on said drill guide adjacent to and connected to said exhaust outlet; and said plenum chamber having an opening exhausting to atmosphere and containing sufiicient volume to substantially reduce the velocity of exhaust air entering said plenum chamber from said exhaust outlet before said exhaust air flows through said opening to atmosphere.

References Cited UNITED STATES PATENTS 1,832,152 11/1931 Stewart 181-36 2,028,320 1/1936 Curtis 181--36 2,136,315 11/1938 Pettit 18136 3,224,527 12/ 1965 Waldron l8 l36 FOREIGN PATENTS 796,067 1/1936 France.

329,237 5/ 1930 Great Britain.

776,884 6/ 1957 Great Britain.

842,192 7/ 1960 Great Britain.

ROBERT S. WARD, 111., Primary Examiner. 

